Forces on a vibrating cylinder in current under lock-in condition

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:260418

Wu, Z ^[1]

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1. Stavanger College (Norway)

This paper presents a sectional model for calculating the hydrodynamic force on a vibrating cylinder section in uniform current under lock-in conditions. A so-called ``fictive velocity`` terminology has been introduced. This is actually a spatially averaged pressure equivalent velocity. The in-line and transverse hydrodynamic force components are treated to be related and are formulated in one single equation. For a stationary circular subjected to current the stagnation point will oscillate in a narrow range on the upstream side of the cylinder surface. When the cylinder vibrates the stagnation point motion characteristics will be influenced. The fluctuating pressure distribution around the cylinder is then converted into equivalent velocity terms, called as ``fictive velocities``, which together with the motion characteristics of the stagnation point, are used to formulate the hydrodynamic force. The model parameters have been estimated by using test results obtained with a horizontally placed circular cylinder forced vibrating transversely to an uniform current. The measured lift force has been corrected for buoyancy effects and the results of parameter estimation are improved.

• OSTI ID: 260418
• Report Number(s): CONF-950604--; ISBN 1-880653-19-2
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
FLUID-STRUCTURE INTERACTIONS
MARINE RISERS
MECHANICAL VIBRATIONS
OFFSHORE PLATFORMS
PIPELINES
RESPONSE FUNCTIONS
WATER CURRENTS
WAVE FORCES